Adjustable wrench



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P 29, 19 1 A. HUFSCHMiD zszlmsgm ADJUSTABLE WRENCH Filed Jan. 10, 1939 )NVENTOR A. HuFscHMm ATTORNEYS Patented Apr. 29, 1941 UNETE STATE$ TNT ()FFICE Application January 10, 1939, Serial No. 250,239 In Switzerland October 15, 1938 1 Claim.

This invention relates to adjustable wrenches of the type having a movable jaw which is slidably mounted upon a shank carrying the fixed jaw at one end, said movable jaw having a recess in which a locking member and a lever are mounted in such a way that at a certain position of the lever the locking member is forced against the shank to hold the movable jaw against movement.

The object of this invention is to effect im provements in a wrench oi the above type and this object is attained by providing the movable jaw with a recesed portion disposed adjacent the shank and spaced lugs extending into said recess, a locking pawl mounted in recess and having an upstanding head disposed between said lugs, a pressure spring disposed between the rear lug and pawl urging the pawl into engagement with the shank, a second pressure spring interposed between the rear lug and the upstanding head and urging the pawl forwardly in said recess, and a pawl operating lever having a cam-shaped end disposed in said recess and interposed between a curved projection at the rear end of said pawl and a curved portion at the rear end of said movable jaw, said lever when moved to one position raising the pawl out of engagement with the shank and when moved to a second position forcing the pawl into locking engagement with the shank.

In order that the invention may be clearly understood and carried into effect embodiments according to by the principles cited above, samples Will now be described by aid of the accompanying drawing in which:

Fig. 1 is a side elevation of an adjustable wrench according to the present invention and showing the movable jaw partly in section and the lever in the loose position.

Fig. 2 is a side elevation of the wrench shown in Fig. 1 showing the movable jaw in the loose position.

Fig. 3 is a side elevation of an adjustable wrench showing all the parts of the movable jaw in the fixed position and illustrating the rear end of the shank of the wrench formed into the fixed jaw of a pincer.

Fig. 4 is a plan view of the wrench shown in Fi .3.

in the embodiments shown in Figs. 1 to 4 the adjustable wrench has a shank I provided with a fixed jaw I. Slidably mounted on the shank is a movable jaw 2 the portion 2' of which forms the gripping jaw surface. The movable jaw is provided with a slot 3 which permits the same to be slidably fitted on the shank I. is enlarged to in which is positioned the locking member 4, the portion 4' of which carries a stop pin 5 limiting the movement of the locking member in the dithe rear end 4 of the locking member 4, a lever B is loosely positioned with an eccentric portion 6' one edge of which is shaped as a toe and engages in a co-acting recess formed in the rear end 4" of the locking member 4. The opposite edge of the eccentric portion 6 bears against the curved surface of the rear end 0' of the jaw portion 2'.

The opposing edges of the shank l and the lower edge of the locking member 4 are provided with serrations l' respectively. As

combined action of a leaf spring 1 which bears against the lower edge of the lug O" of the jaw portion 2 and a coil spring 8 which surrounds the stop pin 5 and which is compressed between the lug 0" and the upstanding portion 4 of the locking member.

For the purpose of adjusting the movable jaw 2 the lever 6 is turned in a clockwise direction thereby causing the shoulder 6" to turn around the oo-acting surface of the rear end 0' of the jaw portion 2'. Consequently the toe-shaped portion of the eccentric 6' which engages in the recess of l" of the locking member raises the same counter to the pressure of the leaf spring I out of engagement with the shank, the movement of the lever 6 being continued until the pin 5 comes into engagemen with the lug 0". Whereas the head portion of the locking member has no serrations, in this position, as can be seen on Fig. 2, the movable jaw' is released and can be adjusted to the new position and upon the release of the lever 6, by the combined action of leaf spring 1 and helical spring 3, it becomes automatically fixed in position. To prevent the non-serrated portion of the locking member coming into contact with the serration of the shank, a. stop 9 is provided on the handle I which limits the rearward movement of the movable aw.

To apply the wrench to a nut N the movable jaw is adjusted on the shank in the manner described above until the jaw portion 2' lightly engages the nut. When the lever 6 is turned in an anti-clockwise direction, the toe-shaped portion of the eccentric portion 8' pivots in the recess of the rear end 4" of the locking member 4, whilst the breast of the eccentric portion 5 acts on the rear end 0 of the jaw portion 2, thus causing the movable jaw to slide forwardly until the jaw portion 2 presses against the nut N, so that the latter is firmly gripped, whilst at the same time the eccentric portion '6' becomes firmly wedged between the rear end 0 of the jaw portion 2 and the locking member, as shown on Fig. 3. When the wrench is in use, the stress on the moving jaw tending to open the wrench will increase the locking of the parts 2, 6, i and I.

When turning the lever E in a clockwise direction, the locking of said parts of the wrench will cease and by the action of the spiral spring 8 the movable jaw 2 wiil slide rearwardly on .the head portion 4 of the locking member 4 and on the eccentric portion 6' of the lever 5, whereby the distance of the gripping jaw surfaces of the jaws I and 2 becomes greater and the nut N is freed.

According to a further embodiment of the invention the locking member may with its end turned towards the fixed jaw be attached to the movable jaw through a pin and slot connection so that it is movable into and out of the locking position, whilst at its free end the locking member acts on an eccentric member similar to 53'.

As shown in Figs. 3 and 4 the wrench may be constructed as a universal tool and as shown incorporates pliers, screw driver, spanner, etc.

To permit the same to be used as special pincers or pliers for tightening or loosening the cones of bicycle free wheels the shank l of the wrench is reduced in thickness for a portion of its length as shown at iii. The reduced portion is bent as at H, H to form the fixed jaw l2 of the special pliers. The movable jaw i2" is formed on one end of a lever i5 which is bent as at H, H so that the two jaws are in alignment. The opposing faces l3 of the jaws may be serrated.

Preferably the lever I5 is detachably aifixed to the shank l by means of a pin M.

The tip of the movable jaw I2" may be formed as a screw driver 15. Similarly the rear end of the lever 15 may be formed as the blade E5" of a screw driver.

Further, one edge of the lever I?) may be provided with a shoulder IE which permits this lever to be used as a spanner for loosening or tightening slotted bearing bushes or the like.

A square slot 11 may also be provided in one edge of the lever for manipulating square headed screws, and the fixed jaw l of the wrench may be provided with one or more hexagonal perforations such as 28.

What I claim is:

An adjustable wrench comprising a shank having a fixed jaw at one end, a movable jaw slidably mounted upon the shank, said movable jaw having a recessed portion disposed adjacent the shank and spaced lugs extending into said recess, a locking pawl mounted in said recess and having an upstanding head disposed between said lugs, a pressure spring disposed between the rear lug and pawl and urging the pawl into engagement with the shank, a second pressure spring interposed between the rear lug and the upstanding head and urging the pawl forwardly in said recess, and a pawl operating lever having a camshaped end disposed in said recess and interposed between ,a curved projection at the rear end of said pawl and a curved portion at the rear end of said movable jaw, said lever when moved to one position raising the pawl out of engagement with the shank and when moved to a second position forcing the pawl into locking engagement with the shank.

ALFRED HUFSCHMID. 

